The latency and bandwidth test the download speed across the wire from the CRM web site to the client browser. A low latency and high bandwidth is ideal. If your values show a high latency and low bandwidth then your CRM experience may be slow depending on the extremity of the range. For some performance reading you can take a look here.

The above documents should give you a solid understanding of performance related improvements you can apply to your Dynamics CRM deployment.

The JavaScript test items are testing your CPU/browser performance of your machine. Ideally you want low values here and upgrading your IE browser to the latest version should give you the best results.

If I remember correctly, the latency and bandwidth tests test the download speed of a file from the CRM web site and calculates these value. A low latency and high bandwidth is ideal. If your values show a high latency and low bandwidth then your CRM experience may be slow depending on the extremity of the range. For some performance reading you can take a look here.

The above documents should give you a solid understanding of performance related stuff.

The JavaScript test items are testing your CPU/browser performance of your machine. Ideally you want low values here and upgrading your IE browser to the latest version should give you the best results.

You can view the source of the diag.aspx page and you will notice 2 JavaScript files. If you locate them and open them up on the server you can see exactly the test being run, what it is doing and the actions being executed. The JavaScript is minified but readable to an extent.